There is a case in which characteristics or a change in characteristics of liquid are performed by measuring a concentration of dissolved gas dissolved in the liquid. For example, as engine oil of a vehicle and oil used in a transformer or various mechanical devices deteriorates, a concentration of hydrogen gas increases, and as a result, when the concentration of the hydrogen gas in the oil is measured, whether the oil deteriorates can be sensed. In actual, it is reported that in the case of the transformer, when dissolved hydrogen of 1000 ppm or more is generated, there is a risk of explosion.
In order to measure the concentration of the dissolved hydrogen gas dissolved in the liquid, methods including an optical method, a viscosity measuring method, an electro-chemical method, a gas chromatograph method, a gas separation method, and the like may be used, but the methods are not a method that can measure a state of the liquid to be measured in real time, and as a result, when it is necessary to determine whether the oil deteriorates on the spot in real time, for example, the methods cannot be methods suitable for application to determine whether the oil deteriorates, and the like. Moreover, in the methods, a measurement device and a measurement process are complicated and besides, there are a lot of problems including a measurement method in that a long-time measurement time is required and high-priced equipment is required, and the like.
Therefore, a device and a method are required, which can sense whether the oil deteriorates by simply measuring the concentration of the dissolved hydrogen gas in the liquid such as the oil in real time.